Hi D,5/16in. or 8mm bore is the correct sizeIf the filter head is a "Norton" typeThe pipes will need some coaxing to stretch over the stubs on the housingBut the will go on, hot water and or a little silicone grease will ease the pain

5/16in. or 8mm bore is the correct sizeIf the filter head is a "Norton" type

John

Cheers John,The filter is a spin-on type from a Honda I believe (at least that is the filter size it takes). I have had one hose off the filter block before and you're right, it is a pain to get back on.

I will have custom fitted braided lines made by ENZED...if I went to a slightly larger diameter just to make fitment to the filter block easier, would this cause problems with pressure/ flow? If slightly larger lines were possible, to what extent? 10mm?